Lapping machine



S. PLAYER LAPPING MACHINE Nov. 30 1925. 1,609,269

Filed July 10, 1923 2 Sheets-Sheet 1 Nov. 30 1926. v 1,609,269

s. PLAYER LAPPING MACHINE Filed July 10. 1923 2 Sheets-Sheet, 2

Patented Nov. 30, 1926.

UNITED STA'I ES PATENT SYDNEY PLAYER, OF WESTBORO, MASSACHUSETTS, ASSIGNQR TO BETHEL-I'LAYER 60., OF WESTBORO, MASSACHUSETTS, A COPARTNERSHIP CONSISTING-OF JOSEPH N. BETHEL AND SIDNEY PLAYER.

.LAIPING MACHINE.

Application filed July 10,

This invention relates to a lapping machine capable of general applicatlon but particularly designed for producing an accurately finished surface on cylindrical or coni B ical work. Such machines operate upon the work by revolving or rolling the work between relatively movable lappingsurfaces.

An important feature of my invention consists in providing a lapping machine in which one lapping surface is relatively fixed and non-rotatable and the other lapping surface receives a combined circular an eccentric motion, the mechanism for producing such motion also forming a part of my invention.

A further feature of my invention relates to the provision of a work spacing or positioning device by means of which the work is held in a selected angular relation during the lapping operation.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invent on 1s shown in the drawings, in which- Fig. 1 is a side elevation partly 1nsection of my improved lapping machine.

Fig. 2 is an enlarged sectional side elevation of the upper and lower laps and parts of the driving mechanism therefor;

Figs. 3 and 4 are detail plan views of separate parts, looking in the direction of the arrows 3 and 4 in Fig. 2;

Fig. 5 is a bottom View of the movable lower lap, looking in the direction"of the arrow 5 in Fig 2, and

Fig.6 is a similar-view of the work spacing. and positioning device, looking in the direction of the arrow 6 in Fig. 2.

Referring to the drawings, I have shown a lapping machine which is in general of the construction disclosed in the prior British patent of J. N. Bethel, No. 216,684 of May 16, 1923. This lapping machine comrises a base or frame 10 having a post 11 slidably supporting an arm 12 having a bearing 13 for a rack bar 14, to the lower end of which is secured the non-rotatable lap 15. The bar 14 and lap 15 are held from rotation but are adjustable vertically by a pinion (not shown) manually operated by handles 16 and held in raised position 1923. Serial No. 650,678.

loose pulleysand 26. Through these connections the drive plate 20 is continuously rotated about the axis of the sleeve 22 and worm gear 23.

A shaft is rotatably mounted in bearings in the sleeve 22, from which it receives motion through differential gears 31, 32, 33 and 34., The gears 32 and 33 are mounted on the same bushing so that they rotate together,and thegears 31' and 34 are secured to the sleeve 22 and shaft 30 respectively. A slight difference in the ratios of the two pairs of gears causes the shaft 30 to rotate at a slightly different speed from the sleeve 22, the amount of speed variation dependin upon the gear ratios selected.

The shaft 30 is provided with a disc 35 having a guide-way 36 (Fig. 4) in which a plate 37 is slidably mounted, the plate being securedin ad usted position by a clam ing screw 38 (Fig. 2). The parts thus far escribed are substantially as shown in the Bethel patent above noted and in themselves'form no distinctive part of my invention.

The slide 37 carries a stud 39 which projects upwardly throughan opening 40 (Fig. 5) in a cross bar 41 fixed in the lower portion of a movable lap 42.

The lap 42 also has a radial groove 43 in its lower face which receives a roll 44 (Fig.

2) on a stud 45 fixed in the drive plate 20. \Vhen conicafl work is to be ground, such as the conical rolls of a common type of roller bearings, the lower face of the fixed lap 15 is formed with a projecting annular surface 46 inclined. at such an angle that it will contact with the upper surface of a conical roller lying on the flat surface of the lap 42. Aring 47 loosely surrounds the projection 46 and prevents radial displace ment of the work. 7

A spacing or positioning device 50 rests ios upon the upper surface of the lap 42 and is provided with slots or recesses 51 to receive and position the conical rolls B (Fig. 6). It has'been found advantageous to position the rolls at an oblique angle to the radius passing therethrough and in the construction shown in the drawings, the angle of 21 has been selected. This angle will, of course, vary with the size and taper of the work and also with the diameter of the la s. The direction of rotation is indicated by t e arrow a. in Fig. 6.

Having thus described the construction of my improved lapping machine, the method of operation will be readily understood. The ring 47 and'spacing plate 50 may be placed on the upper surface of the movable lap 42 and theslots in the spacing plate may then be filled with rolls R while the fixed lap 15 is in raised osition. The lap 15 is then lowered and t e ring 47 is gulded to receive the projection 46. \Vhen the lap 15 is in contact with the rolls R the machine is set in ope-ration and the lap 42 moves under the rolls R with a combined circular and eccentric motion, as the lap is continuously rotated by the roller 44 in the groove 43 and also receives an eccentric motion from the stud 39 projecting through the central opening 40 in the cross bar 41. This combined circular and eccentric motion causes the rolls R to progressively engage a very large proportion of the lapping surface of the lap 42 and produces very desirable results in the work. A substantially" perfect cylindrical or conical form is imparted to the wgrk and the production of surface irregularities orflats is reduced to a minimum.

An important advantage of my improved lapping machine lies in the fact that the outer beveled end. portion of each conical roll is also lapped against the inner face of the rin 47 simultaneously with the lapping of the ody portion of the roll and concentric therewith.

Certain of the advantages of my invention may also be .utilized in the production of flat or non-circular work. I may also set the drive pin 39 concentric with the shaft 30 by placing the clamping screw 38 in a threaded hole .38 located eccentric to the shaft '30 in the disc 35, and swing the upper fixed la 15 to a osition out of axial alignment wit the she. 30. This arran ement I consider less desirable than t at shown and illustrated herein. Having described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed otherwise than as set forth 'in the claims but what I claim is 1. In a lapping machine, a non-rotatable lap, a movable lap, and means to give said movable lap a combined circular and eccentrio movement.

2. In a lapping machine, a non-rotatable lap, a mova le lap, means to continuously revolve said movable lap, and additional means to give said lap an eccentric motion.

3. In ala ping'machine, a non-rotatable lap, a movable lap, means to continuously revolve said movable lap, and additional means to give said lap an eccentric motion, the an lar velocity of the eccentric motion being iiferent from the angular velocity of the circular movement but in the same direction.

4. In a lapping'machine, a non-rotatable dial groove in its lower face, adriving plate having a continuous circular movement and having a driving roll, said roll being received in said groove, whereby said movable lap is given continued circular movement, and additional means to move said lap in an eccentric path.

5. In a lapping machine, a non-rotatable lap, a movable lap, means to continuously revolve said movable lap, and additional means to give said lap an eccentric motion, said latter means comprising a drive pin, means to move said drive pin about an axis eccentric thereto, and means to connect said drive pin to said movable lap adjacent the center of said lap.

6. In a lapping machine, a non-rotatable lap, a movable lap, means to continuously revolve said movable lap, additional means to give said lap an eccentric motion, and driving connections between said first driving means and said additional driving means effective to give the additional driving means a differential motion relative to the first driving means.

7. In a lapping machine, a non-rotatable lap having a circular work engagin projection, a ring loosely fitting said pro ection and forming an outward enclosure for the work, a movable lap and a spacing and positioning plate supported by said movable lap within said ring and having slots therein to lap, a movable lap having a substantially rareceive the work and to hold each piece in spaced relation between said laps.

8. In a lapping machine, a non-rotatable lap, a movable lap, means to give said movable lap a combined circular and eccentric movement, a spacing and positioning plate supported by said lower lap but held from eccentric movement therewith, said plate having slots therein to receive the work and to hold each piece in spaced relation between said laps.

9. In a lapping machine, a non-rotatable lap, a movable lap, means to give said movable lap a combined circular and eccentric movement, a spacing and positioning plate supported by said lower lap but held from eccentric movement therewith, said plate having slots therein to receive the work and to hold each piece of work in spaced relation ing through the piece of work.

10. In a lapping machine for conical work, a non-rotatable lap, a rotatable lap and-a work holder movable on said rotatable lap, said work holder having work receiving recesses each disposed at a definite I angle oblique to the radius passing through the recesses, one of said laps havlng a flat surface and the other lap having an annularportion ofits surface formed as a portion of a cone, both of said laps having line contact with the surface of the conical work when the work is held at the angle determined by the recesses in the work holder.

11. A lapping machine having a non-rotatable lap and a movable lap, and in which the movable lap is iven a circular or revolving movement a out an axis which is offset from the axis oflthe lap', and at the same time is given an eccentric motion with respect to said ofi'set axis.

12. Ala ping machine as claimed in claim 11, whereinrsaid movable lap is given said eccentric motion by rotating the axis or cen- 'ter of the lap about said ofiset axis and wherein means is provided for simultaneously guiding an outer portion of the lap for movement a ong a line radial with respect to said ofi'set axls.

13. In a lapping machine, a non-rotatable lap having a depending circular projection, a rotatable lap, a work-spacing and positioning plate movable on said rotatable lap, and means to hold said plate concentric with said depending projection.

14. In a lapping machine, a non-rotatable lap having a depending circular projection,

a rotatable lap, a work-spacing and position-v ing plate movable on said rotatable lap, and means to hold said plate concentric with said depending projection, said means comprising a ring supported by said rotatable lap and loosely encircling said plate and depending projection.

15. In a lapping machine, a non-rotatable lap, a movable lap, means to continuously revolve said movable lap, and additional means to give said lap an eccentric motion at a differential speed.

' In testimony whereof I have hereunto affixed my signature.

SYDNEY PLAYER. 

